Auditory robustness and resilience in the aging auditory system of the desert locust

After overexposure to loud music, we experience a decrease in our ability to hear (robustness), which usually recovers (resilience). Here, we exploited the amenable auditory system of the desert locust, Schistocerca gregaria, to measure how robustness and resilience depend on age. We found that gene expression changes are dominated by age as opposed to noise exposure. We measured sound-evoked nerve activity for young and aged locusts directly, after 24 hours and 48 hours after noise exposure. We found that both young and aged locusts recovered their auditory nerve function over 48 hours. We also measured the sound-evoked transduction current in individual auditory neurons, and although the transduction current magnitude recovered in the young locusts after noise exposure, it failed to recover in the aged locusts. A plastic mechanism compensates for the decreased transduction current in aged locusts. We suggest key genes upregulated in young noise-exposed locusts that mediate robustness to noise exposure and find potential candidates responsible for compensatory mechanisms in the auditory neurons of aged noise-exposed locusts.